Melbourne, Australia Venus Williams had Nicole Pratt sprawling and sighing.
Justine Henin-Hardenne was in pain and fearing she was finished.
Both advanced to the quarterfinals of the Australian Open today as Henin-Hardenne came back from 1-4 and a late painful cramp to beat Lindsay Davenport 7-5, 5-7, 9-7 in 3 hours, 13 minutes.
Williams stayed on course for a fourth straight Grand Slam final against sister Serena by beating Pratt 6-3, 6-2 in 1:17.
Venus had to save 11 break points and committed 33 errors, but she offset them with 35 winners.
Henin-Hardenne, the fifth seed, went all out to win her battle with the American Davenport, who was seeded ninth.
"I thought I was going to die but I played it with my heart and just went for it," said Henin-Hardenne, the 2001 Wimbledon runner-up.
In the next-to-last game, "I was cramping and then I thought the match was over for me."
She next plays Spain's Virginia Ruano Pascual, a 6-3, 6-3 winner over Czech player Denisa Chladkova.
Venus Williams faces a quarterfinal against No. 7 Daniela Hantuchova, who extended her to three sets in the third round last year, and a possible semifinal against Henin-Hardenne.
Hantuchova, a 19-year-old from Slovakia, beat No. 12 Patty Schnyder 7-5, 6-3.
Serena, the world's top-ranked player and winner of the last three majors, plays her fourth-round match Monday against 18th-seeded Eleni Daniilidou of Greece.